The Quote Checklist I Use Before Ordering Custom-Made Parts

I didn't volunteer to be the person who "gets things made." The job attached itself to my title. Somebody has to turn an engineer's drawing into a purchase order, check that the invoice matches the quote, and explain to accounting why the part that arrived is not the part we approved. That somebody turned out to be me.

I manage purchasing for a 45-person automation company in Anaheim, CA. Not office supplies. The prototype and low-volume custom parts engineers need before a product can ship—roughly $240,000 a year, maybe $260,000, I would have to check the ledger. I keep relationships with seven or eight vendors and report to both operations and finance.

Most content on buying custom parts assumes the reader is an engineer selecting materials or a procurement executive negotiating million-dollar contracts. Not the administrator stuck in the middle. So here is the process I have built since 2020. Six checks, plus a few warnings at the end.

1. Separate parts by process before asking for quotes

If you send a full assembly drawing to a vendor that only runs one type of machine, you waste two weeks. I sort the RFQ before I send anything.

• Flat sheet-metal parts go to a local laser cutting shop.
• Formed panels that need cutouts after bending go to a shop with 3D laser cutting systems. That work is easy to misclassify as flat cutting, and it is not.
• Parts with tight tolerances and threaded details go to a shop that does precision CNC machining in Anaheim, CA. Being local helps when we want to inspect a first article in person.
• Complex housings with internal channels or lattice features go to an additive manufacturing service such as 3D Systems on-demand, not a standard machine shop.

This seems obvious, but there were multiple times I asked a 3D-printing vendor to quote parts that should have been welded sheet metal. Classify first, then compare like for like.

2. Check build volume before you assume it fits

Additive parts are the biggest trap. The marketing page says "large format available," and then the quoting system picks a machine with a different envelope.

Last year we priced a one-piece electronics housing just over 33 inches long. Before sending the file, I searched for 'largest 3D Systems 3D printer build volume' and found a machine spec that seemed big enough. Then the vendor's engineering team called. The part was within the printer's length but not the usable height once they oriented it for stress. We had to split the housing into two pieces, which cost more time than the actual print.

Now I ask three questions before approving any prototyping quote: What is the usable build volume of the actual machine? What is the maximum part dimension after adding supports or nesting? How long is the queue for that specific machine?

I don't have hard data on how often build-volume surprises happen across the industry. I know it has happened to us on three separate projects. That is enough to make me ask.

3. Ask what is NOT included in the price

The frustrating part is that most quote surprises are not dishonest. In 2022, a new shop quoted $8.50 per part for 120 machined components. It was lower than two vendors we had used for years. I approved it. The final invoice was about 30 percent higher.

Nothing shady happened. The quote was $8.50 per part, and it genuinely excluded setup, first-article inspection, deburring, and freight. Those items were buried in the fine print. The shop just never said "here is the total." Now I send one email before any purchase order:

What is not included in this price?

Setup and programming, material certificates, finishing, packaging, and freight show up under a dozen names. Ask specifically about freight. A small part can go USPS at a modest cost—the USPS First-Class letter rate is $0.73 effective January 2025 per usps.com—but a 30-pound aluminum part is not a letter. I want a freight quote in writing, not a surprise on the invoice.

The vendor who lists all fees up front, even when the total looks higher, usually costs less in the end. I trust a transparent total more than a low unit price with asterisks.

4. Verify material claims and certifications

For anyone selling into aerospace, defense, or regulated industrial markets, material origin matters. I ask for a material datasheet and a certificate of conformance on the quote itself. If the quote says "ABS-like resin," I ask which resin and who made it. If the supplier cannot tell me, I cannot pass that information to our customer.

Environmental claims deserve the same scrutiny. If a vendor calls a printed part or material "recyclable," I ask how and where. Per FTC Green Guides (16 CFR Part 260), a recyclable claim should be accurate for consumers who actually have access to recycling programs. If the supplier cannot name a take-back program or a recycling channel, that word should not be in the proposal.

5. Do a ten-minute intellectual property check

This is the step most buyers skip. When a supplier says they use a proprietary or patented process to make your part, take ten minutes to look it up.

A few months ago, one of our engineers sent me a capability statement for a laser processing vendor. The brochure referenced a 'chaotic cavity fiber laser patent' in the middle of a technical paragraph. I do not have hard data on who owns that patent family or how enforceable it is. That is a question for our counsel, not for me. But the ten-minute search stopped us from approving the quote without asking the supplier to confirm, in writing, that they had the right to use the process they were selling.

You do not need to become a patent attorney. You need to know one thing: if a vendor's unique process is protected by a patent, that can affect sole-sourcing, pricing, and your own legal exposure. A simple PO clause saying the supplier represents that it has the rights to use the processes in the quote has saved us more than once.

6. Agree on inspection, invoicing, and nonconformance handling

Two administrative points that never make it into engineering blogs.

First, acceptance. Before I approve a PO, I ask what happens if the parts are late or dimensionally wrong. Will the vendor provide a first-article inspection report? Do they rework at their cost or send a credit? If the answer is "we will figure it out," I have learned that I will be the one figuring it out.

Second, paperwork. I once ordered from a small shop whose owner said, "I'll write you a receipt." I ordered anyway. Accounting rejected the expense—about $2,400, maybe $2,600 with shipping, I would have to check—and it came out of my department budget. Since then, I confirm before ordering that a vendor can issue a proper invoice with a tax ID, a PO number, and line items that match the quote. If you have ever tried to explain a handwritten receipt to a finance team, you already understand why this is a check.

Final warnings

Do not pay for artificial emergencies. When a rush quote comes back with a $400 premium, ask when the part is actually needed. We have paid for more than one "urgent" order that sat in receiving for a week. I don't have hard data on how many rush orders were truly necessary, but my honest guess is less than half.

And watch your search terms. If you type 'how much are CO2 laser treatments' because you are trying to benchmark laser cutting or engraving prices, you will find results from a completely different industry. In a job shop, a CO2 laser treatment usually means cutting, engraving, or surface processing of a material. Price depends on material, thickness, quantity, and finishing, so there is no single per-treatment number. Ask for a quote with a drawing instead. If you were actually looking for cosmetic treatment pricing, this article will not help you.

That's the checklist. It is not glamorous, and it takes extra time. But if "can you get this made?" lands on your desk, it beats learning these lessons from the accounting department.